We propose to develop a commercially viable very small field of view (VSFOV) solid-state gamma camera. The intended use is to provide intro-operative imaging in sentinel lymph node biopsy procedures for staging breast cancer and melanoma. The camera will enhance the data available to the surgeon by providing an image of a 2cm x 2cm area as compared to the single-detector probes in general use today. The core imaging detectors which will be incorporated into the proposed device are currently under development at Lawrence Berkeley National Labs and Capintec under a CRADA. Successful prototypes of several core detectors have been developed previously, but not used in a camera. Development of production core detectors will be completed in the first half of 2001, making them available for use in the VSFOV camera. The proposed camera, data acquisition electronics and dedicated readout are outside the scope of the CRADA. The solid-state VSFOV camera is a potentially powerful tool, surpassing currently available-technology. Not reliant on large photomultiplier tubes, it will be light enough to be hand-held and thin enough to position in anatomically difficult areas. It can be applied directly to the region of interest, improving efficiency and decreasing imaging time. PROPOSED COMMERCIAL APPLICATIONS: Biopsy of the first tumor-draining lymph node, the sentinel lymph node has become the standard of care in staging breast cancer and melanoma--the market is established and growing rapidly. These biopsy procedures rely on single-detector probes to identify radioactive nodes. The proposed device will offer the surgeon imaging data previously unavailable during the procedure, which we expect will improve the effectiveness and efficiency of the procedure.